What doesn't limit the range of moton from the things which you've mentioned would be age. Age per se doesn't really limit the range of motion - while there are factors which negatively influence our range of motion and which are strongly correlated with age, it is hard to say that age itself would be the cause of a limited range of motion.
Slouched and in fetal position.
Galactose. It's a sugar found in many dairy foods. Monosaccharides may also be the answer;it's the basic component of carbohydrates.
It usually take half lives